Didn't get the expected O.G

I brewed a nano batch of single grain IPA and I don't know what I have done wrong.

Before I started, I calculated the O.G. and F.G. as shown in the picture bellow. After boiling the wort from 5.3 liters to 4.4 liters (~1 hour), I measured the O.G., and found it only to be 1.074 (pre-boil was 1.065).

The beer is in a small carboy now, so I haven't measured the F.G. yet.

Brewing process:

  1. Heated up 4.4 liter of water to 72° Celsius (~161° Fahrenheit)
  2. Added crushed grains, the temp is now around 67° Celsius (~152° Fahrenheit)
  3. Turned off the stove and waited for an hour, but kept the temperature over 65° Celsius (~149° Fahrenheit)
  4. Started lautering with a sieve and washed the grains with warm water(around 67° Celsius), ended up with 5.3 liters of wort
  5. Started boiling the wort. After it reached boiling point, I turn down the heat the stove
  6. Still boiling a little bit for an hour while I added some hops. After the hour I got 4.4 liters of wort left. Measured the O.G. at 1.074. (used this calculator to get the right O.G. from hot wort)
  7. Cooled the wort down and racked it to the carboy added yeast

Is there anything I'm doing wrong?

Are there some common causes for not achieving an expected O.G.?

Topic smash final-gravity ipa original-gravity homebrew

Category Mac

1
answered at

Besides the potential causes that @mdma cites (possibly mash is too thick, leading to poor contact of water with grain and poor sparging), which can be solved by having a more liquid mash (at least 0.55L of strike water per kg of grain, or 1.3 qts. per lb.), a primary cause is the fact that your efficiency tends to decline as your grain volume (OG) increases.

1
answered at

The key piece that's missing here is extraction efficiency - how much sugar you can get out of the grains.

In the calculator, it's set at 80%, but it's doubtful you got that just from steeping and lautering in a pot. You typically need continual recirculation to get 80%+. With my old equipment (a large cooler with a hand-made series of pipes with slits.) I used to average 70%.

So, my guess is you did nothing wrong, other than you don't know the efficiency of your brewing system yet. Now you know the actual preboil OG you got, you can use that to work out your typical efficiency.

Your actual efficiency is

65 / 96 * 0.80 = 54%

This is typical for steeping small batches since a lot of the grain doesn't come into contact with much water, especially during sparging. Next time, just put in 55% into the calculator and your OG will come out more in line with what is planned.

Efficiency is a complex topic - for tips on finding out where you are losing efficiency see Troubleshooting Brewhouse Efficiency, and focus on the mash extraction and lautering sections.

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